Electronic filter

About: Electronic filter is a research topic. Over the lifetime, 13207 publications have been published within this topic receiving 93063 citations. The topic is also known as: filter.

Arcing fault detection module

Abstract: An arcing fault detection module (4) for detecting arcing faults in an electrical current distribution circuit (8) comprises a filter circuit (9) and an autocorrelation circuit (10). The filter circuit (9) is electrically connected to the distribution circuit (8) and samples current with the distribution circuit. The filter circuit (9) includes a band pass filter (12) to filter out fundamental and high frequency components from the sampled current, and a comparator (13) to convert the sampled current to a digital signal. The autocorrelation circuit (10) receives the digital signal from the filter circuit (9). The autocorrelation circuit (10) includes a plurality of shift registers (15-18) for storing the digital signal for a predetermined sample period, and a plurality of EXCLUSIVE-OR gates (35-37,41, 43, 44) and OR gates (38, 39) to detect odd and even harmonic signals. An integrator-counter (47) electrically connects to certain EXCLUSIVE-OR and OR gates, and provides an arc indicative signal when the absolute value of the even and odd harmonic signals is equal to a predetermined number.

Branching filter package

Abstract: A branching filter package has a SAW filter chip housing area which houses a piezo electric base, on which a transmitting SAW filter and a receiving SAW filter having a different frequency passing band with each other, are formed, and an impedance matching circuit and a branching circuit for the transmitting SAW filter and the receiving SAW filter.

System and method for varying low audio frequencies inversely with audio signal level

Abstract: The present invention relates to an auto loudness circuit for performing loudness compensation automatically depending on the signal level. When the signal level decreases, loudness compensation is slowly introduced and as the signal level increases, loudness compensation is quickly removed. To do so, the auto loudness circuit utilizes a filter circuit with the characteristic of a first order bass boost. The filter circuit maintains a corner frequency which is proportional to the inverse of audio level in order to mimic the Fletcher-Munson curves. Because the circuit employs a capacitance-multiplier with a first order resistance capacitance filter, the bass boost is inversely proportional to the signal level. Thus, bass boost is achieved automatically as the program content changes so that the listener is unaware of significant changes in program material as signal levels change either through increase or decrease in volume, crescendo or new material.

Active controllable filter circuit using variable transconductance amplifier

Abstract: An RC active filter circuit wherein the active elements of the circuit are realized by controllable transconductance amplifiers. The transfer response of the filter circuit is readily variable by altering signals applied to the control terminals of the transconductance amplifiers.

Methods and apparatus for tuning an LC Filter

Abstract: A receiver, such as a television receiver, tunes an inductive (“L”) and capacitive (“C”) filter based on a desired frequency. The LC filter includes a plurality of inductors, configured in at least one inductive (“L”) bank, and a plurality of capacitors configured in at least one capacitive (“C”) bank. The inductors are selectively enabled for the LC filter by an N code, and the capacitors are selectively enabled for the LC filter by an M code. The receiver uses a functional comparator to compare offset, capacitive, inductive and frequency values to tune the LC filter. Techniques for tuning the LC filter for operation in the VHF and UHF bands are disclosed.